Average is excellent for Marin coho

Being average is welcome news in the world Marin's endangered coho salmon.

With the spawning season winding down, Marin Municipal Water District officials are reporting the number of coho egg nests — called redds — are at average in number and they are the most seen in the Lagunitas Creek watershed in six years.

The number of actual fish — although the final tallies are not in — are expected to be about 500, also at average based on counts first taken in1995-96.

"We are excited," said Eric Ettlinger, aquatic ecologist for the Marin Municipal Water District, which oversees the watershed. "We have been very fortunate with the weather pattern this season and that has helped."

Heavy rains in December helped facilitate the return of the coho from the sea to their spawning grounds. The coho complete a three-year life cycle that sees them born, travel to open sea, then almost miraculously return to spawn and die.

The December rains were followed by a dry January that kept the egg nests and young fish from being swept away.

"This is a case where average is good news," Ettlinger said.

The endangered coho salmon was said to be in an "extinction vortex" after its numbers dipped to all-time lows three years ago. But number have been on rise since then.

While the news is encouraging, Ettlinger cautioned the species — listed as endangered by the federal government — is not out of the woods by any stretch.

"There could be spring storms that could cause problems for the fish," he said. "There are any number of things that could make it hard for them to survive."

But there is cautious hope.

Ocean conditions were very good for coho salmon in 2012, according to the federal Northwest Fisheries Science Center. Physical conditions improved and plankton were abundant, including the copepods and fish larvae that make up coho salmon's preferred prey.

Looking forward, the center predicts these favorable conditions will continue through 2013, which bodes well for Lagunitas Creek coho.

If the coho currently in the ocean are surviving at a rate similar to what water district observers saw this season, there could more than a thousand coho salmon return this fall, Ettlinger noted.

Local efforts to help fish survive may have also played a role.

"In the end, it involves each of us as individuals understanding how important it is to be connected to these ecological processes that are around us," Supervisor Steve Kinsey said at a recent coho conference in the San Geronimo Valley.